A segmented mould mainly comprises two lateral shells that each mould one of the lateral sidewalls of the tire, and a plurality of segments that mould the tread of the said tire and are radially movable between an open position and a closed position of the mould. The shells and the segments define an interior moulding space that is intended to be brought into contact with the unvulcanized green form of the tire.
In order to form cuts or patterns on the tire tread, the mould segments notably comprise lining sipe blades projecting out into the interior moulding space. These sipe blades form a negative of the tread patterns that are to be moulded in the tread of the tire.
Conventionally, these lining sipe blades are formed by cutting and pressing or stamping a sheet-metal blank. However, these methods of manufacture are suited only to obtaining sipe blades having a thickness less than or equal to 2 millimeters, for example those used for moulding passenger vehicle tires.
Now, there is a need to manufacture lining sipe blades of greater thicknesses, for example for moulding tires for construction plant vehicles.
To this end, it is conceivable to produce lining sipe blades formed as one with the associated segment of the mould. However, this solution entails machining a solid block of material, and this is particularly expensive. Furthermore, the space separating two adjacent lining sipe blades may not be wide enough to allow the machine tool to pass.
The present invention aims to remedy these drawbacks.